131066215978 has 4 divisors (see below), whose sum is σ = 196599323970. Its totient is φ = 65533107988.

The previous prime is 131066215949. The next prime is 131066215979. The reversal of 131066215978 is 879512660131.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 879512660131 = 7 ⋅125644665733.

It can be written as a sum of positive squares in only one way, i.e., 86085320409 + 44980895569 = 293403^2 + 212087^2 .

It is not an unprimeable number, because it can be changed into a prime (131066215979) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32766553993 + ... + 32766553996.

Almost surely, 2^131066215978 is an apocalyptic number.

131066215978 is a deficient number, since it is larger than the sum of its proper divisors (65533107992).

131066215978 is an equidigital number, since it uses as much as digits as its factorization.

131066215978 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 65533107991.

The product of its (nonzero) digits is 544320, while the sum is 49.

The spelling of 131066215978 in words is "one hundred thirty-one billion, sixty-six million, two hundred fifteen thousand, nine hundred seventy-eight".